The body parts that can grow back are the skin, the vas deferens and large organs which includes the liver.
Although some patients who have a diseased portion of their liver removed are unable to regrow the tissue and end up needing a transplant.
The fingernails, toenails and hair can also grow back.
The parts of the human body that continue to grow as people age are the ears, nose, hair, and nails.
While the hair and nails continue to grow because they are made to be cut or broken, the ears and nose grow for different reasons.
Regeneration of many body parts in humans is blocked in humans primarily because scar tissue is formed after an injury.
One possible solution would be to administer drugs that impart the ability to regenerate tissues and even organs and stop scars from forming.
Humans do not regrow their limbs.
Although, interestingly enough, there are sporadic reports in the medical literature of people regrowing certain organs.
For example, kidneys, and this is very rare, but there have been reports.
We do regenerate our liver.
The calves are regarded to be one of the most difficult muscles to build for two reasons.
People already have a degree of calf development, and this makes it harder to drive further development.